The intravenous (IV) administration of immune globulin (WIG) is the primary treatment of individuals with immune deficiencies. Although the initial IVIG preparations caused severe side effects, the IVIG preparations available at the present time are well tolerated in the majority of immune deficient patients. Nonetheless, a small proportion of patients continue to have unpleasant, even disabling, reactions such as headache, fatigue, and myalgia. Fever and chills remains a problem, especially when patients have intercurrent infections. The reactions often persist despite trying other IVIG preparations or pre-medicating with acetaminophen, diphenhydramine, and corticosteroids. Further, due to the requirement for IV administration, there are issues with patient compliance.
Subcutaneous (SQ) administration of immune globulin is an alternative to intravenous administration. Compared to IV infusions, SQ administration of immune globulin has several advantages. For example, it reduces the incidence of systemic reactions, does not require sometimes-difficult IV access, improves trough levels, and gives patients more independence. Because of the difficulty in administering large quantities of fluid in a single site, it is necessary to do SQ infusions once or twice a week, using two to as many as 5 sites at a time. Thus, unlike WIG, which is given once a month, subcutaneous administration is usually done weekly. Hence, there is a need for alternative methods for administering immune globulin.